A vSphere 5.x implementation contains two ESXi hosts, ESXi01and ESXi02. There is a virtual machine “VM21” connected to the Production port group on ESXi01.
ESXi01 has the following switch configuration.
vSwitch0, single uplink to 10.1.20.0/24
Production port group
VMkernel port for vMotion
VMKernel port for management
vSwitch1, single uplink to 10.1.40.0/24
Engineering port group
VMKernel port for NFS storage
ESXi02 has the following switch configuration.
vSwitch0, single uplink to 10.1.20.0/24
Engineering port group
VMkernel port for vMotion
VMKernel port for management
vSwitch1, single uplink to 10.1.40.0/24
Production port group
VMKernel port for NFS storage
Which two statements are true about this configuration? (Choose two.)
A.
vMotion is not available between the two hosts
B.
If VM21 is migrated to ESXi02 it will not be available on the network
C.
The virtual machine can be vMotion migrated to the target host.
D.
Broadcasts from the Production port group will not reach the Engineering port group.
I really don’t get this question. In reading it, the networks look the same(?) If so, why is B correct? And no idea why VMware keeps asking network broadcast questions, either.
No it is not the same. On ESX01, Production port group is on VS0 which is connected to 10.1.20.0/24 network. Let’s say on the physical side, it is in one VLAN. Engineering port group is on VS1 and connected to 10.1.40.0/24 network. If VM21 from Production group (10.140.20.0/24 network) is migrated to ESX02, it will end up connected to VS1 Production group port, which is connected to 10.1.40.0/24 network (different VLAN). So answer B is right. I’m not sure about answer D.
Ah, I see it now, thank you.
Good observation Ricky
Re: D (broadcasts)
check pg 20 (I don’t think in ver. 5 it’s different)
http://www.vmware.com/pdf/vsphere4/r40/vsp_40_esx_server_config.pdf
Each port group is identified by a network label, which is unique to the current host. Network labels are used
to make virtual machine configuration portable across hosts. All port groups in a datacenter that are physically
connected to the same network (in the sense that each can receive broadcasts from the others) are given the
same label. Conversely, if two port groups cannot receive broadcasts from each other, they have distinct labels.
But why is C: incorrect?
I think C is correct,not D.
If vmkernels with vmotion enabled have same name,vmotion should work….
Boradcasts from the production portgroup on esxi01 (.20/24) will most certainly reach the engineering portgroup on esxi02 (.20/24). How is D correct?
A: false
vmotion is aivalable on vswitch0 on both esxi hosts in network 10.1.20 so vmotion should work
B: true
Vm21 is connected to prod port group witch is 10.1.20 on Esxi01 but on Esxi02 prod port group is 10.1.40 so vm will not be reachable on the network
C: true
vmotion is aivalable on vswitch0 on both esxi hosts in network 10.1.20 so vmotion / migration should work
D: false
Broadcast from production on Esxi01 witch is 10.1.20 will reach Engineering on Esxi02 witch also has 10.1.20 as uplink so when both Esxi hosts have vm’s running, vm’s on Esxi01 in prod can reach vm’s on Esxi02 from engineering and vice versa.
vSphere vMotion Networking Requirements
(ESXi and vCenter Server 5.1 Documentation)
Ensure that virtual machines have access to the same subnets on source and destination hosts.
B and C are correct.
D.
Broadcasts from the Production port group will not reach the Engineering port group.
YES they will – Port Groups are not associated with IPs, rather VLANS – in this case with the combination of both HOSTs – the Port Groups straddle both VLANS – A VLAN is by definition just a broadcast domain… So regardless of IP the packets will span both.
Also B basically states the VM will vmotion over and become available, because vmotion is just looking for PortGroup name matches.
Strictly speaking B is not states the VM will vmotion over, there are another ways to migrate VM.
Each port group is identified by a network label, which is unique to the current host. Network labels are used to make virtual machine configuration portable across hosts. All port groups in a datacenter that are physically connected to the same network (in the sense that each can receive broadcasts from the others) are given the same label. Conversely, if two port groups cannot receive broadcasts from each other, they have distinct labels.
I took a while to get it, because I’m new to VMware, but B and D are right..
A INCORRECT: vMotion is available (if the VM is not connected to the port group)
B CORRECT: you can COLD migrate the VM, but the port group label is different so it won’t have connectivity in the other host
C INCORRECT: you can COLD migrate it, but NOT VMOTION it, because the port group labels are not consistent.
D CORRECT: same as C, the label are distinct so broadcast cannot be received (see other comments for explanation).
Sure is that this is a tricky-not-a-1-minute question for the exam..damn vmware!
Thanks you all for the comments!
D is wrong since the two port groups share the same physical switch VLAN (because they are on the same network) broadcast from Prod PG on Esxi01 will reach machines from Eng PG on Esx02 and vise versa .
C is correct because although the VLAN are not the same but the vmotion checks if a PG with the same lable exists on the destination host and in this case both Prod and Eng PGs are available on both host .
Luay,
Unfortunately the question doesn’t state that they are using a standard or a distributed switch. But assuming they are on a standard switch, then there’s 2 things from the documentation to understand for vMotion.
“If you are using standard switches for networking, ensure that the network labels used for virtual machine port groups are consistent across hosts. During a migration with vMotion, vCenter Server assigns virtual machines to port groups based on matching network labels.”
“Ensure that virtual machines have access to the same subnets on source and destination hosts”
Based on the 2 statements above, if you were to vMotion VM21 somehow, vCenter will automatically choose the same label “Production” port group on ESXi02 which is not on the same subnet as ESXi01’s “Production” port group. Therefore, vMotion will fail. So C is incorrect.
And to confirm, plus this one is a lot easier to understand.
“Conversely, if two port groups cannot receive broadcasts from each other, they have distinct labels”
So Answer is B and D